Swivel chair



FIG. 1 is a rear perspective view of a swivel chair showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings are for the purpose of illustrating portions of the swivel chair that form no part of the claimed design. 

CLAIM The ornamental design for a swivel chair, as shown and described. 